Process for the preparation of a syndiotactic polyolefin

Claim 1

A process for the preparation of an essentially isotactic olefin polymer by polymerization or copolymerization of an olefin of the formula R a --CH═CH--R b , in which R a and R b are identical or different and are a hydrogen atom or a hydrocarbon radical having 1 to 14 carbon atoms, or R a and R b , together with the atoms binding them, may form a ring, at a temperature of -60° to 200° C., at a pressure of 0.5 to 100 bar, in solution, in suspension or in the gas phase, in the presence of a catalyst which is composed of a metallocene as a transition metal compound and an aluminoxane of the formula (II) ##STR12## for the linear type or of the formula III ##STR13## for the cyclic type, where, in the formulae (II) and (III), the radicals R 14 may be identical or different and are a C 1 -C 6 -alkyl group, a C 6 -C 18 -aryl group or hydrogen and p is an integer of from 2 to 50, wherein the metallocene is a compound of the formula I ##STR14## in which M 1 is a metal of group IVb, Vb or VIb of the Periodic Table, R 1 and R 2 are identical or different and are a hydrogen atom, a C 1 -C 10 -alkyl group, a C 1 -C 10 -alkoxy group, a C 6 -C 10 -aryl group, a C 6 -C 10 -aryloxy group, a C 2 -C 10 -alkenyl group, a C 7 -C 40 -arylalkyl group, a C 7 -C 40 -alkylaryl group, a C 8 -C 40 -arylalkenyl group or a halogen atom, R 3 and R 4 are identical or different and are a hydrogen atom, a halogen atom, a C 1 -C 10 -alkyl group which is optionally halogenated, a C 6 -C 10 -aryl group, a --NR 2 15 , --SR 15 , --OSiR 3 15 , --SiR 3 15 or --PR 2 15 radical, in which R 15 is a halogen atom, a C 1 -C 10 -alkyl group or a C 6 -C 10 -aryl group, R 5 and R 6 are identical or different and have the meaning stated for R 3 and R 4 , with the proviso that R 5 and R 6 are not hydrogen, ##STR15## where R 11 , R 12 and R 13 are identical or different and are a hydrogen atom, a halogen atom, a C 1 -C 10 -alkyl group, a C 1 -C 10 -fluoroalkyl group, a C 6 -C 10 -aryl group, a C 6 -C 10 -fluoroaryl group, a C 1 -C 10 -alkoxy group, a C 2 -C 10 -alkenyl group, a C 7 -C 40 -arylalkyl group, a C 8 -C 40 -arylalkenyl group or a C 7 -C 40 -alkylaryl group, or R 11 and R 12 or R 11 and R 13 , together with the atoms binding them, each form a ring, M 2 is silicon, germanium or tin, R 8 and R 9 are identical or different and have the meaning stated for R 11 , m and n are identical or different and are zero, 1 or 2, m plus n being zero, 1 or 2, and the radicals R 10 are identical or different and have the meanings stated for R 11 , R 12 and R 13 .